The invention relates to an electric apparatus with thermal protection comprising:
on the one hand, a contactor with a wall which extends between a fixing base having a latch adapted to cooperate with a profiled rail and to be unlocked by a tool, and which has, in the vicinity of its front face, power terminals and at least one signaling terminal, and PA0 on the other hand, a thermal relay with an association face which has conducting pins adapted to penetrate into these terminals for establishing an electric connection and for fixing the relay by placing this face in the immediate vicinity of this wall.
In known apparatus, whose construction complies with that mentioned above, and which are very widely used for supplying motors, it is necessary to dissociate the thermal relay from the contactor in order to have access to the fixing latch and change this apparatus; this requirement is due to the fact that the locking hook is generally placed in a plane of symmetry of the contactor which itself passes through a region of the thermal relay containing the conducting pins connecting it to the terminals of this contactor.
Changing a single contactor is in fact not a very frequent operation, for the number of operating cycles which the contacts of power switches can carry out is chosen to be appreciably greater than that which will be effectively used; however, the deterioration of an electromagnet coil or the need to re-organize equipment inside a control cabinet, form possibilities which the constructor must take into account in order to facilitate the work of the maintenance staff.